Subject:
LEVELS OF PROTEIN STRUCTURE Primary Structure?the unique sequence of amino acids, type sequence and number; determines the other three structures It is held together by peptide bonds between the carboxyl group of one amino acid with the amino group of another amino acid B. Secondary Structure? regular repeated coiling and folding of the polypeptide caused by H?bonds between atoms in the polypeptide backbone (a hydrogen on a nitrogen and a double?bonded oxygen atom) see Fig. 5.20 p. 76 a. alpha helix? a delicate coil held together by hydrogen bonding between every fourth peptide bond b. Beta pleated sheet? where regions of the chain lie parallel to each other LEVELS OF PROTEIN STRUCTURE
